Process for bleaching fibrous cellulose material containing fastdyed figures



Patented Jan. 10, 1939 UNITED STATES PATENT OFFICE PROCESS FOR BLEACHING FIBROUS CELLU- LOSE DYED FIGURES MATERIAL CONTAINING FAST- No Drawing.

Original application March 11,

1937, Serial No. 130,417. Divided and this application March 2, 1938, Serial N0. 193,605

3 Claims.

This invention relates to bleaching processes, more part cularly to a process for bleaching fibrous cellu.ose material containing fast-dyed figures, and is a division of my co-pending application for patent filed March 11, 1937, Serial Number 130,417.

Standard bleaching processes are relatively complicated and lengthy as, for example, the bleaching of cotton yarn, which involves substantially seven steps, as follows'z-boiling in caustic, as 2% caustic soda, 1% silicate and 1% sulphonated oil or the like, dropping the above bath and washing in hot water, dropping and running through. hypochlorite 'solution, to 2 Tw., dropping and washing in warm water, dropping and souring in a hydrochloric acid or sulphuric acid solution or the like, dropping and Washing in warm water, dropping and washing in water to which is added bluing.

An object of this invention is to provide a bleaching process which is much shorter than standard processes, and involves fewer steps.

Another object is to provide a bleaching process employing a compound containing oxygen and chlorine which process will inhibit the characteristic action of the chlorine upon the fibers without interfering with the action of the nascent oxygen.

Still another object is to provide an improved bleaching process which will be eflicient, even if the material to be bleached contains insoluble oils.

Another object is to provide a bleaching process which will, leave the material free of oil stains, chafe marks and so-called niger beads.

Yet another object is to provide a bleaching process which is considerably less expensive than most standard bleaching processe for like material.

Other objects and advantages of the invention will be apparent during the course of the following detailed description thereof.

In the sodium hypochlorite-bufier hereinafter referred to, the buffer may be glues, saponified and/or emulsified fats and oils, sulphonated oils, dextrines, glucose, sugar, fatty alcohols, alkali and alkaline salts.

The sodium hypochlorite and buiier may be mixed together in substantially the following proportions:

' 1, Percent by weight Sodium hypochlorite Buffer s 5 However, the percentages of sodium hypochlorite may vary between 95% and 99% while the Water gallons 200 to 250 Sodium stearate "percent" 2 to 3 Sulphonated oil percent 2 to 3 The material is treated in this bath, with the latter at a temperature between 100 F. and 111 F. for a period of substantially ten minutes whereupon there is added between 8% to 10% p of the sodium hypochlorite-bufier mixture and treatment continued for from fifteen to twenty minutes, whereupon the temperature is raised to, preferably, 180 F. to 190 F. (altho this temperature may vary between F. and 190 F.). The higher temperature range is maintained for about twelve minutes after which the bath is dropped and fresh water of between 200 and 250 gallons containing from 1% to 2% sodium stearate (high titre), with bluing if desired, is-

employed as a rinse, the rinse being maintained at a temperature of from 100 F. to 110 F. over a period of substantially five minutes, whereupon the surplus may be extracted and the material dried.

With the treatment described, the chlorine does not attack the material being bleached, due to the proportions of buffers employed and the temperatures maintained.

Various changes may be made to the forms of the invention herein described, without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. A bleaching process for fibrous cellulose material containing fast-dyed figures, which consists in treating said material for substantially ten minutes at 100 F. to a bath comprising water, sodium stearate, and sulphonated oil, adding to said batha mixture of sodium hypochlorite and a buffer, maintaining said bath at a temperature of between 100 F. and 110 F. for substantially fifteen to twenty minutes, increasing the temperature of said bath to substantially F. over a period of about twelve minutes, and dropping said bath.

2. A bleaching proces for fibrous cellulose material containing fast-dyed figures, which consists in treating said material for substantially ten minutes at 100 F. to a bath comprising water, substantially 2 each of sodium stearate and sulphonated oil, adding to said bath substantially 9% of sodium hypochlorite-bufl'er mixtin'e, maintaining said bath at a temperature of between 100 F. and 110 F. for substantially fifteen to twenty minutes, increasing the temperature of said bath to substantially 180 F. over a period of about twelve minutes, and dropping said bath.

3-. A bleaching process for fibrous cellulose material containing fast-dyed figures, which consist in treating said material for substantially ten minutes at 100 F. to a bath comprising water, sodium stearate and sulphonated oil, adding to said bath a mixture of sodium hypochlorite and a buffer, maintaining said bath at a tempera- 110 F. over a period of substantially five minutes.

EDWIN P. SHERMAN. 

